Stable and wavelength-tunable RSOA- and SOA-based fiber ring laser

• A stable and wavelength-tunable fiber ring laser by using RSOA and SOA is proposed and performed.
• The proposed fiber laser can be directly modulated at 2.5 Gbit/s QPSK-OFDM signal within 50 km fiber transmissions.
• It could be a cost-effective and promising candidate for the standard-reach and extended-reach WDM-PON or TWDM-PON.

In this work, we propose and experimentally investigate a wavelength-tunable fiber ring laser architecture by using the reflective semiconductor optical amplifier (RSOA) and semiconductor optical amplifier (SOA). Here, the wavelength tuning range from 1538.03 to 1561.91 nm can be obtained. The measured output power and optical signal to noise ratio (OSNRs) of the proposed fiber laser are between -0.8 and -2.5 dBm and 59.1 and 61.0 dB/0.06 nm, respectively. The power and wavelength stabilities of the proposed laser are also studied. In addition, the proposed laser can be directly modulated at 2.5 Gbit/s quadrature phase shift keying-orthogonal frequency-division multiplexing (QPSK-OFDM) signal and 20–50 km single-mode fiber (SMF) transmissions are achieved within the forward error correction (FEC) limit without dispersion compensation. It could be a cost-effective and promising candidate for the standard-reach and extended-reach wavelength division multiplexed passive optical network (WDM-PON).